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The SX25A6 is the first 6xAA light I've tested from Eagletac. And what a place to start – incorporating many of the build elements and options of their recent GX/SX/MX25L2 and TX25C2 series lights, but in an AA battery format.

Like those other recent lights, the SX25A6 similarly sports the new XM-L2 emitter, available in both Cool and Neutral White options. Let's see put my sample through its paces and see how compares to other high-output lights of this multi-AA battery class …

Manufacturer Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).

As with the recent GX/SX/MX25L2 models, the SX25A6 comes securely packaged in the new Eagletac cardboard box packaging. The light comes in a soft fabric pouch with a drawstring. Included accessories are extra o-rings, manual, and warranty card. Note that my sample came in kit form, with the secondary-switch tailcap and full accessories. The kit will be described further below, but includes a holster and filter/diffuser covers.

The SX25A6 is in keeping with other 6xAA-size lights, and is quite reasonable for the class overall.

Note below that my SX26A6 is the kit version, which comes the secondary tailcap switch.

The overall build of the SX25A6 is reminiscent of some of the recent Eagletac lights (e.g., GX/SX/MX25L2), but with some key adaptations for the multi-AA market.

Similar to those other lights (in standard head form), ergonomics are good, with the light well balanced and with reasonably good grip. Knurling is of reasonably high aggressiveness, and is present over the entire battery tube/handle, with an additional band on the head. There are also finger well cut-outs on three sides of the battery tube.

Anodizing is glossy black, hard anodized (i.e., type III), with no obvious chips or damage on my sample. Labels are bright and clear (i.e., sharp white against the black background).

The SX25A6 doesn't use a battery carrier (like most the multi-AA competition), but instead has cut-out well for the cells. The cells are arranged in continuous series, with connection being made by contacts on a connector piece in the tailcap. This connector can spin freely, and locks in place to a couple of holes in the body that line up with rods in the tailcap.

Screw threading on the tailcap is traditional triangular cut, and is anodized. Surprisingly, this actually allows you to lock out the light – on most lights with this sort of battery arrangement, the current is not carried by the body (and hence no lock-out is possible). In this case, there is a connection from the tailcap through the body, so you can easily lock-out the light by a simple twist of the tailcap.

Screw threads are square-cut (and thick) in the head region where mode switching occurs, like with the other recent Eagletac lights

The SX25A6 can tailstand, even with the secondary tailcap switch tailcap. This is a special tailcap available with the kit version, as there is an additional current path for the light in this form. The switch functions exactly the same as the main switch. I must say, I find the kit tailcap to be remarkably compact for the inclusion a secondary switch.

Both versions of the light (i.e., default flat tailcap, and secondary switch tailcap) have the main electronic side-switch in the head for on-off, with output mode selection and programming controlled by head twist. This is the same as the other recent GX/SX/MX25L2 and TX25C2 lights – they all use a distinctive set of contact points in the head, required for mode switching (scroll down for a UI discussion).

Main switch feel is good for an electronic switch – there is a reasonable traverse, and the action is firm. Grip is good with the texturized rubber button cover. The secondary tailcap switch on the kit version has a similar feel and function, but is recessed for tailstanding.

The SX25A6 reflector is very smooth and surprisingly deep – this should translate into very good throw for the size. The XM-L2 emitter (Neutral White T6 in my sample) was well centered.

The kit version of the light has a scalloped stainless steel bezel ring, replaceable with the screw-on diffuser/filter assembly.

Optional YRGB kit (also includes diffuser and holster):

The SX25A6 kit comes with the standard screw-on style filters/diffuser. In this case, the stainless steel bezel ring is removed and a plastic filter/diffuser holder is screwed in its place. A similar arrangement was seen in my recent Eagletac GX/SX/MX25L2 lights. Note that the diffuser pieces themselves appear to be made of glass, for all models.

Eagletac is using high-quality optical glass filters (as opposed to just colored plastic or glass). The one exception is the red filter, which is just a colored piece of glass. See my GX25L2/SX25L2 review for how this compares to a true red filter.

Along with the YRGB filters and diffuser, the kit versions also come with a holster. The holster for the SX25A2 doesn't have a closed bottom, and holds the light to just below the head. Hold was good, and enough of the light sticks out, allowing for easy draw access.

User Interface

The interface is similar to recent GX/SX/MX25L2 and TX25C2 models. Turn the light on/off by the electronic switch. Press and hold for momentary, press-release (i.e. click) for locked-on.

There are three output levels controlled by how loose/tight the head is (i.e., the three levels are accessed in sequence from head fully tight). As soon as you loosen past fully tight, you drop down to the second level. You drop down again to the third (and final) level after a ~120 degree turn. This is the same as the TX25C2, but differs from the G25C2 and GX/SX/MX25L2 series lights (that offer four modes). You need to do at least one and a quarter full head turns from tight to get the light to shut off (but you can easily lock out the light at the tailcap).

There are two possible groups of output modes available - Tactical (100% > 15% > Strobe, in sequence) and Regular (100% > 40% > 0.5%, in sequence). You can switch between the two groups by turning the light on max (fully tight) and loosening the head to the second level and then back to tight, repeating this sequence ten times in five seconds.

A new feature on these recent tactical lights is the ability to rapidly access a momentary Turbo from any head position by a press-and-hold of the switch when On. You can similarly access strobe at any time by a double press and hold (i.e. click and press-hold). Simply release the switch to return to your previous head-set level.

To access the hidden auxiliary modes, do a quick loosen-tighten twist of the head (from first level tight to third level and back again). Repeat this twist to advance through the modes. Mode sequence is: Strobe I > Strobe II > Hi-Flash > SOS I > SOS II > Beacon > Lo-Flash, in repeating sequence. Turn off the light or loosen the head to quit the hidden modes. I will describe these modes in more detail below.

There is an "energy saving feature" where the light reduces output by 25% after 200 seconds in Turbo. You can toggle this feature "off", which results in a 10% step-down instead. See my runtime results below for more information. To toggle this feature off or on, turn the light on at the third level, and switch back and forth to the second level for ten times in five seconds.

Video:

For more information on the light, including the build and user interface, please see my video overview of the whole series:

Video was recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen.

As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.

PWM/Strobe

There is no sign of PWM that I can see, at any output level, on any light – I presume the lights are current-controlled.

My SX25A6 is very similar to my TX25C2 and GX/SX25L2 in its auxiliary blinking modes.

Strobe I:

The main strobe is standard high frequency strobe, measured at 9.5 Hz on my SX25A6

Strobe II:

The second strobe mode is an alternating or "oscillating" strobe, switching between 6.5Hz and 15.1Hz every 2 seconds.

Hi-Flash:

Hi-Flash is basically a full power slow strobe/beacon mode. Frequency was a reasonable ~1.6Hz. Note that the deflection spikes you see above are just the on and off signals of the pulse (i.e., it spends roughly half the time on, half the time off, with each pulse).

SOS I:

The "fast" SOS signals the full SOS sequence (dot-dot-dot, dash-dash-dash, dot-dot-dot) in just under 3 secs. Note again that the traces above refer to both the on- and off-signal for each pulse of light.

SOS II:

In contrast, the "slow" SOS takes just under 3 seconds just do the "S" (i.e. dot-dot-dot), and about 4 second to do the "O" (i.e., dash-dash-dash), with a good 3 seconds in-between each Morse code letter. Personally, this seems far more useful than the rather frenetic initial SOS mode.

Beacon:

Beacon is a slow full output flash (almost 2 secs long), re-occurring approximately every ~14 secs (i.e., a very slow beacon)

Standby Drain

A standby current drain is inevitable on this light, due to the electronic switch in the head (and/or tailcap). Without the tailcap in place, I have measured this standby drain as 113 uA. Given the 6s1p arrangement, for 2000mAh Eneloop NiMH that would translate into just over 2 years before fully-charged cells would be completely drained.

Like the other recent Eagletac lights, that is clearly a low standby drain, and not a concern. If you are worried however, you can easily lock-out the SX25A6 by a quick twist of the tailcap (at leaast on my kit version of the light). Note that a tailcap lockout is not common on multi-AA lights (as the the tension in the springs usually carries the current). But the secondary tailswitch on my kit version of the SX25A6 has a separate path through the body, for dual-switch functioning.

Beamshots:

And now the white-wall beamshots. All lights are on Sanyo Eneloop NiMH, at the maximum supported number for the given models (4x, 6x or 8x). Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences (i.e., my SX25A6 sample is a neutral white tint, but you won't be able to tell that below).

As you can see, the SX25A6 has surprisingly good throw for a light this size. Spillbeam width is narrower than most lights in this class, due to the relatively deep reflector. Output is certainly very high, even on my T6 Neutral White sample. Scroll down for detailed tables comparing the throw to other lights in this multi-AA class.

Of course, the true test will be in outdoor shots. The snow is nearly gone here, so I should be able to get to these soon. In the meantime, here are some indoor shots. These will at least allow you to compare the throw and spill of the three lights. For your reference, the back of the couch is about 7 feet away (~2.3m) from the opening of the light, and the far wall is about 18 feet away (~5.9m). Below I am showing a series of exposures, to allow you to better compare hotspot and spill.

I will update these comparisons with outdoor shots when available.

UPDATE JUNE 18, 2003:Below see a comparison of the SX25A6 to the Nitecore EA8.

For outdoor beamshots, these are all done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground).

FYI, any "streaks" you see across the images are bug-trails. Flying insects are often attracted to the bright lights, and their flight trails get captured as swirly streaks due to the long exposure time.

The EA8 is slightly "throwier" than the SX25A6, as you would expect for the larger head and smooth reflector. But the difference isn't that great really – I wouldn't expect throw to be a major discriminator for most people. Scroll down to see exact measures in my summary tables.

Testing Method:

All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

Keep in mind that my SX25A6 uses the Neutral White T6 output bin. I would expect the Cool White U2 emitters to be on average ~7% brighter than my sample (actually, anywhere from ~1-13%, depending on where the in the bins everything falls).

In any case, my SX25A6 is my highest output multi-AA light at the moment, and one of my best throwing. On this later point, my beam intensity measurements (which are done with a NIST-certified light meter according to ANSI FL-1 testing standards) are higher than the Eagletac specs. I have noticed a similar pattern of above-spec performance in my recent Eagletac XM-L2 light reviews.

What about overall output performance?

As with my other recent Eagletac reviews, my output measure estimates for my SX25A6 are very close to the published ANSI FL-1 specs. Note that Eagletac only publishes specs for the Cool White U2 version, so I had to adjust down their ANSI FL-1 lumen values by 7% for the Neutral White T6.

Note as well that mode spacing for the SX25A6 is very similar to TX25C2, which not everyone is a fan of (i.e., there are relatively few Med/Lo modes).

XM-L2 vs XM-L
I realize all this emitter talk may seem confusing, especially for those that don't keep up on the fine details of LEDs.

Basically, these new XM-L2 emitters are very similar to the old XM-L, but built on a new process. Directly comparing back to XM-L is complicated by the more stringent testing and reporting measures Cree is now using for XM-L2 output binning. But there is actually an easy conversion - if you look up the Cree spec tables under the same conditions, you will see that the new XM-L2 bins are exactly two bin steps brighter than the same bin number on XM-L. So a XM-L2 T6 is basically the same thing as a XM-L U3. This is part of the reason for the switch to the new process - there is now more "headroom" on the new XM-L2 platform, and higher output XM-L2 emitters can ultimately be produced.

In terms of lumens though, you have to keep in mind how the binning process works. Given the ~7% range within each bin, this means that for any given specific XM-L2 sample could be anywhere from ~7-20% brighter than a comparably bin-numbered XM-L sample. This is presumably where that "up to" 20% brighter statement comes from in the Cree literature. But you need to keep in mind that on average, a XM-L2 T6 should be ~13% brighter than a XM-L T6, for example. You really have to think of these things statistically – the bins are a range, and you don't know where exactly in the range any given sample will fall.

Output/Runtime Graphs:

Note: for the sake of the runtimes, "Hi" is 100% and "Med" is the 40% output mode. The dotted line is when the step-down from Hi is turned "off" (i.e., reduced to just a 10% step-down instead of 25%)

As expected, the SX25A6 is very bright on its Hi (100%) setting. The default is for the light to step down 25% after 200 secs on Hi. With this feature turned off, there is a smaller 10% drop. In either case, the light remains largely in flat regulation over the course of the run – even on alkalines, which is very impressive.

Note that as alkaline batteries drain down, the main LED begins to flash. For the Hi (100%) mode runs, this only happened once the light had clearly fallen out of regulation. But on the Med (40%) runs, the light started showing occasional flashes ahead of falling out of regulation (note that this was specific for alkalines, in my testing).

Overall efficiency is excellent for the SX25A6, considering the number of batteries and emitter used (recall my sample is the XM-L2 T6 NW). To explain what I mean by that, you have to consider the difference in the output bin reporting structure of the XM-L2, as explained above.

Eagletac's ANSI FL-1 runtime specs are generally consistent with my results. Recall that the FL-1 standard calls for time to 10% output (not 50%, as reported above), and that I am using relative low-capacity 2000mAh Sanyo Eneloop.

Potential Issues

As with other Eagletac models where output mode is set by the degree the head is tightened, you need to keep all contact surfaces in the head scrupulously clean.

Similar to the TX25C2, mode spacing is a bit unusual, with only three levels per group and no typical "Lo" mode (i.e., you basically get to choose between Turbo > Hi > Very Lo, or Turbo > Med > Strobe). See my lumen estimates above for more info.

Light lacks any sort of anti-roll feature, and can roll fairly easily.

Preliminary Observations

The SX25A6 is the highest output multi-AA light in my collection at the moment (although the Nitecore EA8 is a close second). Performance of the 6xAA SX25A6 is excellent at all levels, with surprisingly good regulation on standard alkalines.

There is certainly a lot in common with the TX25C2 that I have recently reviewed – overall build, user interface, and output levels are all very comparable. For that matter, even the runtimes are about the same – the main difference is that it takes 6xAA to equal the performance of 1x18650. But there are some perks to the larger build – you get great throw on the SX25A6, for example.

As with the TX25C2, I like the head-twist interface for output levels, and find the electronic side-switch works well. Note that my kit version of the SX25A6 also contains a secondary tailcap electronic switch (with appropriate current path through the body), for those of you who prefer that switch arrangement. The tailcap switch exactly duplicates the function of the side switch.

While I like the interface on these new Eagletac models, I miss the 4-level modes of the GX/SX/MX25L2 and G25C2-II series. Output level spacing on the 3-level TX25C2 and SX25A6 is a little unusual ( i.e., you really only have the choice between Turbo > Hi > Moonlight or Turbo > Med > Strobe on these lights).

The standby current is minimal on the SX25A6, as it is on all the recent Eagletac models I've been testing (i.e., over 2 years on standard 2000mAh AA cells). And you can easily lock out the light at the tailcap for long-term storage.

The SX25A6 also shares the same kind of excellent output/runtime efficiency as its Li-ion-based siblings. As I alluded to above, I am particularly impressed that Eagletac can maintain excellent regulation for so long on standard alkaline cells. That said, I did notice that the low voltage warning flashes start early on alkalkine cells (i.e. before falling out of regulation). But I saw no issues on NiMH cells, which is what I recommend you run the light on.

As before, I appreciate seeing the kit options for these new Eagletac lights. For the cost, it seems to me the diffusers/filters, holster and extra switch are worth it on the SX25A6.

It's nice to see Eagletac bringing the design and features of its popular new CR123A and LI-ion models to the AA battery space. The 6xAA arrangement seems like a good compromise to maintain such high output, while still providing good regulation. It is also quite throwy for its relative size, which I suspect many here will like. Definitely a serious contender in the multi-AA class.

Is it difficult to press the tail-switch? (is the switch not to deep into the light)

No, it's easy enough to access - the switch is flush with the level of the tailcap external ring. Since it is an electronic switch, you can easily presss it with your thumb or index finger (depending on how you are holding the light).

Another nice review, Selfbuilt. Glad you put the ITP A6 in the table, as I have that light too... and I have to agree that it doesn't fare very well in comparison! Um, I did notice that your beamshot photo labels say SX25A2 instead of A6... thought you would want to know.

Mine is the non-tailswitch version, and lockout works the same as your sample. Just a short turn stops output.

I would have wished for some anti-roll shaping in this light. But I was able to attach the lanyard and loop it around the body, then use the friction grip thing on the lanyard to tighten it into place around the body. Now it can't roll very far.

For me this is a great interface. One can glance at the light before hitting the switch and know at what level it will come on, from the position of the switch relative to the printed logo.

Another nice review, Selfbuilt. Glad you put the ITP A6 in the table, as I have that light too... and I have to agree that it doesn't fare very well in comparison! Um, I did notice that your beamshot photo labels say SX25A2 instead of A6... thought you would want to know.

Thanks, I'll fix it later today. Eagletac is actually quite consistent and logical with their last two ending digits of their model numbers ... but when you do as many lights as I have recently, it's easy to mess up the occasional label!

Mine is the non-tailswitch version, and lockout works the same as your sample. Just a short turn stops output.

Excellent, glad to hear it. Couldn't be sure if that was the case for all lights, as only the tailswitch version would need the current path functionality.

What is the lumen value of the small step down? Looks to be ~205 ROLO.
Your little Selfbuilt est. lumens chart has 970 & 740, and I take it that 740 is the 'energy savings' mode output, correct?

Sorry, I didn't put it into the estimate lumen table. The energy-saving step down (25%) drops to 740 lumens by my estimate. With energy-saving turn "off" (10% step-down), it drops to ~870 lumens. I will update the table with both sets of numbers tomorrow.

Originally Posted by InquisitiveInquirer

Is there any chance that like the Nitecore EA8, this can run on only 4 AA if in a pinch?

I'm afraid not. The EA8 uses a 4s2p arrangement, so it can easily run on 4xAA. The SX25A6 is 6s1p, so you need to have all six batteries in place to establish a connection.

I've added to the review an outdoor beamshot comparison of the SX25A6 to the Nitecore EA8.

For outdoor beamshots, these are all done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground).

The EA8 is slightly "throwier" than the SX25A6, as you would expect for the larger head and smooth reflector. But the difference isn't that great really – I wouldn't expect throw to be a major discriminator for most people.

I am currently testing the GX25A3, and will update this thread with additional beamshots once that one is ready.

For a 6xAA light with neutral T6, the halo effect is less pronounced than the 8XAA TK41 I returned, and handling is easier. It is throwy-ish but wider illumination which I find more useful in a general flashlight. Good household light with some heft and not too bulky. This is a pricey light, but I like the double A format which doesn't have a carriage or battery rattle like my old LD40. For EDC try Quark pro AA if you like AA alternative to 1X16850.

Similar to the TX25C2, mode spacing is a bit unusual, with only three levels per group and no typical "Lo" mode (i.e., you basically get to choose between Turbo > Hi > Moonlight, or Turbo > Med > Strobe). See my lumen estimates above for more info.

I realize terms like Moonlight and "Lo" are fairly subjective, but I am curious if you really meant to call 11 lumens Moonlight and not low? I personally find 11 lumens quite substantial and actually too much for tasks I frequently do. For instance, reading a book in bed at night with my wife already asleep I find:

.1 lumens enough
.3 lumens perfect
5 lumens will wake my wife up from a dead sleep and she'll groan, "Turn that thing off!"
11 lumens even if I'm alone and don't have to worry about disturbing anyone is too much for me.
(Of course intensity factors greatly in there as well - this is just a really rough guide on my part.)

I realize terms like Moonlight and "Lo" are fairly subjective, but I am curious if you really meant to call 11 lumens Moonlight and not low?

You are right, I shouldn't have used the word "moonlight" - more of a "very lo", I guess (review edited). The SX25A6 (and TX25C2) certainly don't have a moonlight mode. It's just that the difference between levels across the two sets of spacings is pretty severe at the low end (i.e. to jump from ~10 lumens to ~450 lumens on standard mode). Most others tend to give you an option in-between there.

I remember nitecore used to have a +/- 141000 size Li-Ion battery in one of their double AA sized lights.
I'm thinking 3 of those in this light - AND a built in charger for both NiMH and Lith Ion would really be hot!

Throw in 4 modes like the G series, spaced the way I want them, add a flip up diffuser and I'd happily line up to pay double the MSRP!